The instant invention relates to surgical equipment and procedures and more particularly to a novel surgical wire and to a method for the use thereof for interconnecting two or more adjacent bone structures and/or adjacent portions of fractured bone structures.
A significant factor in the healing process for any bone fracture is the degree to which the fractured portions of bone can be maintained in properly set orientations during the healing process. The problems of properly setting and securing fractured portions of bone structures are solved relatively easily in cases of relatively minor bone fractures where the fractured bone portions can be set without surgery and thereafter maintained in proper orientations with external splints or casts. However, in cases where more serious or complicated fractures are involved, surgery is often required to properly set the fractured portions of bone, and various types of hardware, such as screws, pins, and wires, are frequently required in order to secure the fractured bone portions in properly set orientations. Although many of the surgical procedures which are utilized for setting bone structures have become relatively routine, there is always a risk that surgery will result in inadvertent damage to nerves, tendons, or other portions of the anatomy.
Fractures of the vertebrae in the spinal column are often very serious fractures, particularly because they frequently involve damage to the spinal cord which can result in varying degrees of paralysis. Further, surgery is often required to set and/or immobilize fractured vertebrae in order to assure proper fusion of the fractured portions of bone, and even the most delicate heretoforeknown surgical procedures have, on occasion, resulted in inadvertent damage to the spinal cords of patients. One frequently used procedure for setting a fractured vertebra in the spinal column, particularly in the cervical area of the spinal column, is to wire the fractured vertebra to one or more adjacent vertebrae in order to provide support for the fractured vertebra to assure that it is retained in a desired orientation during the healing process. The procedure which has heretofore been followed for installing wires in the spinal column is an extremely delicate one, which requires the passing of one or more surgical wires beneath the laminae of one or more vertebrae so that the wire or wires actually pass through the spinal foramen of the vertebrae adjacent the spinal cord. While a properly installed wire which is positioned so that it is adjacent the wall of the foramen beneath the lamina can be accommodated in the spinal foramen of a vertebra for an indefinite period of time without causing substantial trauma to a patient, the heretofore-known procedures for installing such wires have been extremely delicate procedures, and they have, on occasion, resulted in irreparable damage to the spinal cords of patients.
The heretofore-known surgical procedures for passing surgical wires beneath the laminae of vertebrae have generally been carried out by using a surgical instrument comprising an elongated handle portion to which a curved tubular end portion is secured, the end portion having an open tubular terminal end. In order to install a wire in the spinal column of a patient, the wire is inserted into the curved tubular end portion of the instrument, and the end portion is then inserted into the spinal foramen beneath the lamina of a vertebra. Thereafter, further portions of the wire are passed through the curved end portion of the wire passing instrument until the end of the wire can be grasped with a plier or similar grasping instrument, and then the instrument is backed out or withdrawn from the spinal foramen leaving the wire in position beneath the lamina. Once the wire has been passed through the spinal foramen in this manner, it can then be urged into contact with the surface of the lamina so that it does not press against the spinal cord, and the wire can be secured to a portion of an adjaent vertebra in order to provide support or fixation for the fractured vertebrae.
While the heretofore used surgical procedures for installing surgical wires between vertebrae have been successful in a majority of the cases in which they have been applied, they are extremely delicate procedures, and a number of instances have occurred wherein these procedures have resulted in substantial permanent damage to the spinal cords of patients, and in some cases patients have suffered substantial paralysis. Sometimes damage of this type has occurred during the insertion and removal of the curved tubular end portions of instruments through the spinal foramen of the vertebrae of patients. This is particularly true because of the fact that in order to accommodate a surgical wire in the tubular end portion of an instrument of this type, the overall configuration and the sectional dimension of the curved tubular end portion of the instrument must be relatively large, considering that the end portion must actually be passed through the foramen of a vertebra. In this regard, the radius of curvature of the end portion must be great enough to permit a wire to be passed therethrough without binding significantly, and the sectional dimension of the end portion must be relatively large for similar reasons. Further, the tubular opening in the terminal end of the tubular end portion provides an area for tissue, etc., to catch on the end portion as it is passed through the foramen. In addition, the overall construction of the instrument with an elongated handle which is attached to the end portion makes the instrument difficult to manipulate with the degree of precision required for spinal surgery. All of these structural features of the instruments heretofore used for installing wires in the spinal column have contributed to making the heretofore-known surgical procedures for installing surgical wires extremely delicate and high-risk procedures.
Further, oftentimes the heavy guage wire, because of its thickness, cannot be safely passed under the lamina of the spinal foramen. In such instances a compromise is often effected either by reducing the width of the lamina by removing some of the bone of that lamina, thereby weakening that supporting structure and hence jeopardizing the integrity of the fusion, or by using a smaller gauge of wire to effect the boney stabilization, only to have that wire break in the post operative period before bony fusion has occurred, thus again leading to failure of the operation.
The instant invention effectively overcomes these and other disadvantages of the heretofore-known surgical apparatus and procedures for interconnecting adjacent bone structures with surgical wires and the like. The surgical wire of the instant invention comprises an elongated flexible and malleable main portion, a flexible and malleable tapered portion which integrally extends from an end of the main portion, and a flexible and malleable leader portion which is of substantially reduced diameter with respect to the main portion and extends integrally from the reduced end of the tapered portion. The surgical wire of the instant invention is used in the method of the instant invention by first threading the leader portion around a bone structure, preferably by using a surgical needle attached to the leader portion, and then advancing the leader portion so that the main portion of the wire extends around the bone structure. Thereafter the method is completed by securing the wire to an adjacent second bone structure to interconnect the two bone structures, whereby one of the two bone structures provides support for the other.
While the use of the surgical wire of the instant invention in a variety of different surgical procedures of this general type is comtemplated, it has been found that the surgical wire of the instant invention has particular application in a surgical procedure for interconnecting adjacent vertebrae of the spinal column, particularly in the cervical area of the spinal column, to promote proper fusion of the portions of a fractured vertebra. The method of the instant invention for interconnecting adjacent vertebrae comprises interconnecting the vertebrae with the surgical wire of the instant invention by first attaching the leader portion of the wire to a curved surgical needle and then passing the needle through the spinal foramen of a vertebra so that it passes in contact with or at least closely adjacent the wall of the spinal foramen beneath the lamina of the vertebra, and then further advancing the leader portion so that the tapered portion and a portion of the main portion of the surgical wire pass through the spinal foramen in contact with or closely adjacent the wall thereof. The method is then completed by securing the opposite end portions of the main portion to an adjacent vertebra to interconnect the two vertebrae. Preferably these steps are carried out in a series of manipulative operations wherein sequential portions of the wire are gradually urged through the spinal foramen of the vertebra while a certain amount of tension is applied to the opposite end portions of the surgical wire in order to maintain the portion of the wire which is located within the foramen in contact with or at least closely adjacent to the wall of the foramen beneath the lamina so that that the wire does not press against the spinal cord. Further, preferably the surgical needle which is used in the method has a sectional dimension which is generally similar to the sectional dimension of the main portion of the surgical wire, and the leader portion of the surgical wire is threaded through an eye in one end of the needle to interconnect it thereto. Accordingly the sectional dimension of the needle is minimized, and the combined sectional dimension of the needle and the leader portion where it is interconnected to the needle is also minimized in order to minimize the sectional dimension of the hardware which is passed through the foramen. Further, the radius of curvature of the needle can be selected to precisely fit the requirements of each application, and since the needle is only connected to the leader portion which is highly flexible as a result of its reduced diameter, the needle can be delicately manipulated with a high degree of freedom and mobility as it is passed through the foramen. It has been found that for these reasons, when adjaent vertebrae are interconnected in accordance with the method of the instant invention, the risks to the patient are substantially reduced as compared to the risks associated with the heretofore-known methods.
Heretofore-known apparatus representing the closest prior art to the surgical wire of the instant invention of which the applicant is aware are disclosed in the U.S. patents to DePage U.S. Pat. No. 887,074; Carruthers U.S. Pat. No. 2,093,145; Pearson et al U.S. Pat. No. 3,130,728; and Kaufman et al U.S. Pat. No. 3,125,095. However, since none of these references teach the specific structural features of the surgical wire of the instant invention, they are believed to be of only general interest. They are also believed to be of only general interest with regard to the method of installing the wire in accordance with the instant invention.
Accordingly, it is a primary object of the instant invention to provide an effective surgical wire for interconnecting adjacent bone structures in surgical procedures.
Another object of the instant invention is to provide an effective method of interconnecting adjacent bone structures in surgical procedures.
Still another object of the instant invention is to provide an effective method of interconnecting adjacent vertebrae in the spinal column without causing damage to the spinal cord.
An even further object of the instant invention is to provide an improved wire for securing and immobilizing a fractured vertebra in order to promote proper fusion of the fractured portions of the vertebra.